GRAIN-ORIENTED ELECTRICAL STEEL SHEET, TRANSFORMER CORE, TRANSFORMER, AND METHOD FOR REDUCING TRANSFORMER NOISE

摘要

Provided is a grain-oriented electrical steel sheet with which it is possible to achieve low-noise performance when the steel sheet is formed into the iron core of a transformer and used in practical operation.A grain-oriented electrical steel sheet includes an insulating film. The insulating film has a chemical composition containing Si, P, O, and at least one selected from Mg, Ca, Ba, Sr, Zn, Al, Mn, and Co and a crystallinity of 20% or more, and a minimum tension provided to the steel sheet by the insulating film at a temperature of 100°C to 200°C is 10 MPa or more. It is preferable that the static friction coefficient of the insulating film be 0.21 or more and 0.50 or less. It is preferable that the insulating film contain no Cr.